Analysis of carbapenem-resistant Acinetobacter baumannii carbapenemase gene distribution and biofilm formation

Lin Wang; Qi-Wei Chen; Yan-Chun Qin; Xue-Li Yi; Hong Zeng

Analysis of carbapenem-resistant Acinetobacter baumannii carbapenemase gene distribution and biofilm formation

Int J Mol Epidemiol Genet. 2024 Feb 15;15(1):1-11. eCollection 2024.

Authors

Lin Wang^{1

2

3

4}, Qi-Wei Chen⁵, Yan-Chun Qin^{1

2

3

4}, Xue-Li Yi⁵, Hong Zeng^{1

2

3

4}

Affiliations

¹ School of Basic Medical Sciences, Youjiang Medical University for Nationalities No. 98 Chengxiang Road, Baise 533000, Guangxi, PR China.
² Guangxi Technology Innovation Cooperation Base of Prevention and Control Pathogenic Microbes with Drug Resistance, Youjiang Medical University for Nationalities Baise 533000, Guangxi, PR China.
³ Guangxi Zhuang Autonomous Region Engineering Research Center of Clinical Prevention and Control Technology and Leading Drug for Microorganisms with Drug Resistance in Border Ethnic Areasn Baise 533000, Guangxi, PR China.
⁴ Key Laboratory of The Prevention and Treatment of Drug-Resistant Microbial Infecting, Youjiang Medical University for Nationalities, Education Department of Guangxi Zhuang Autonomous Region Baise 533000, Guangxi, PR China.
⁵ The Affiliated Hospital of Youjiang Medical University for Nationalities No. 18 Zhongshan Second Road, Baise 533000, Guangxi, PR China.

PMID: 38505565
PMCID: PMC10944714

Abstract

Objective: In recent years, Acinetobacter baumannii has been appearing in hospitals with high drug resistance and strong vitality, which brings many difficulties to clinical treatment. In this study, 255 strains of A. baumannii were isolated from Youjiang Medical University for Nationalities Affiliated Hospital clinical samples and found to be highly resistant to carbapenems. The drug resistance, biofilm-forming ability, and carbapenase gene distribution of 145 carbapenem-resistant A. baumannii (CRAB) strains were analyzed statistically.

Methods: The clinically isolated strains were detected using Vitek mass spectrometry and Vitek2-compact for bacterial identification and susceptibility testing, respectively. The biofilms of clinical isolates were quantitatively detected by microplate crystal violet staining, and qualitatively observed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). And the common carbapenemase genes were detected by polymerase chain reaction (PCR).

Results: The 255 clinical isolates from the Youjiang District of western Guangxi Province had a high resistance rate to carbapenems antibiotics. The main specimens were from the intensive care unit (49%), and the most important specimens were sputum specimens (80%). All 145 strains of CRAB produced different degrees of biofilm, and six carbapenenase genes were detected. We found that there were significant differences in biofilm formation between resistant and sensitive strains of tobramycin, levofloxacin, ciprofloxacin, tigecycline, and doxycycline (P<0.05). The distribution of bla_OXA-23 and bla_OXA51 genes was significantly different from CRAB biofilm formation (P<0.05). In addition, AmpC, bla_OXA-23, bla_OXA-51, and TEM genes were more distributed in antibiotic-resistant strains.

Conclusion: The clinical strains have a high resistance rate to carbapenems, and the CRAB with bla_OXA-51 and bla_OXA-23 genes has a high resistance to antibiotics and a strong biofilm.

Keywords: Carbapenem-resistant Acinetobacter baumannii; biofilm; oxacillinases.